I actually lay awake last night wondering about my (un)healthy obsession with all things old and British. I'm no expert on British social, political or economic history, but I managed to pinpoint a few facets of these areas that particularly fascinate me. Cut me some slack, because I gleaned all this "knowledge" from my little historical fiction novels (Sharon Kay Penman and Elizabeth Chadwick, she of the historical novels, not the bodice-rippers):

1. Everyone spoke French. That's weird. Not only that, but depending on the kind of French you spoke, people could determine from whence in England or France you hailed, and whether you were nobly born or not.
2. If you weren't nobly born, your life was worthless. Too bad, so sad.
3. Unweddable girls/women were sent to convents. This happened if you were poor, ugly, orphaned or widowed.
3.5. Weddable girls/women were also sent to convents, but usually only if they posed a threat to whoever was in power at the time. Edward I sent an infant Welsh princess to a convent because he was afraid she might grow up and raise arms against him; she lived all her 54 years there.
4. Some widows voluntarily went to convents -- I imagine because they couldn't envision life without their formerly alive husbands.
5. However, if you were a rich or otherwise valuable widow (read: extraordinarily beautiful), you better beware because men will just KIDNAP you off the road when you go out to market, even though you have your ladies in waiting and men-at-arms with you. Almost happened to Eleanor of Aquitaine, but her big burly man of a future husband, Henry, got her first.
6. Men battled their fathers, sons and brothers, and imprisoned or executed their wives, mothers, mothers-in-law, sisters, young cousins, etc. Edward III killed his own brother George (who was a real jerk, but still).
7. Everyone drank wine. With everything. At all times. Morning, noon and night.
8. It took days to march your army 20 miles (to battle your brother, of course), but no one knew you were there until you were standing outside the castle walls. You'd think all that chain mail and armor made some noise...
9. There's quicksand in the middle of England.
10. Spouses didn't really like each other all that much.
11. Children didn't really like their parents all that much.
12. If you were a man charged and found guilty of treason, they would hang you but cut you down before you died, slit you open, pull out your intestines, burn your private parts with a hot poker, show you your intestines, then let you bleed to death. If the King was in a good mood, they would just behead you and depending on the level of your birth and your treason, would probably stick your head on top of a city gate so everyone could see the price of rebellion. Ewww.
13. Everyone was avenging something or someone.
14. Women were always pregnant.
15. Women were always miscarrying.
16. Brunette women were considered ugly. (Hey!)
17. Princesses wore green velvet wedding dresses.
18. Illegitimate children of Welsh royalty had equal inheritance rights; illegitimate children of English royalty (and there were TONS) didn't. Thus, all the civil wars (see # 6).
19. Family members were just offered as ransom here and there. "Hey, let's end our little war. I'll give you my first child Bob and my brother Tim, in exchange for you getting off my land." A bit flippant perhaps, but the gist is the same.
20. They ate a lot of eel dishes.

I have learned much. I hope our short review has been helpful to you.